This invention relates to a process and apparatus for treating organic wastes, particularly food wastes to allow a highly biodegradable material to be pumped to anaerobic digesters where they are converted into a fertilizer-type material and renewable energy such as methane gas.
Municipal solid waste collection and disposal is a major world wide problem. Disposal by burial has resulted in serious depletion of suitable sites. Existing dump sites are continuously emitting global warming methane and carbon dioxide gases which are difficult to collect. Many such dump sites, indeed have caused methane fires which are difficult to extinguish. As bottom liners deteriorate, leachate has entered and contaminated the ground water system at many sites. Disposal by incineration has become more questionable as energy prices have increased and contamination of the air has become an increasing problem.
Recognition of the problem has resulted in the development of many processes to convert municipal solid waste into commercially useable products such as soil amendments, fertilizer and methane gas which can be used to produce heat or to generate electricity.
Some of these processes attempt to convert unsorted general municipal waste into commercial products by collecting unsorted waste which may contain, food wastes, paper, cardboard, glass, metal cans, rags, yard waste, farm wastes, food processing plant wastes, wood, metal objects and other wastes too numerous to catalog. Processes which attempt to recycle unsorted municipal wastes are expensive involving many different types of heavy expensive sophisticated equipment, manual labor for sorting, and substantial supplies of fuel and electricity.